Centrifuge for the separation of serum from cheese constituents



Feb. 8, 1949.

G. CENTRIFUGE FOR THE SEPARATION 0F J. sTREzYNsKl 2,461,129

SERUM FROM CHEESE CONSTITUENTS Filed April 20, 1944 Patented Feb. 8,1949

y A. 2,461,129 cENTnrrUGE Fon 'ma snrm'nou or moeurs "sEaUM non cansan; cons' George J. S

Chicago, ll., to

tremukl. The De Laval Separator Company, No' York, N. Y., a corporation of New Jersey ApplicationV 20, .1944, Serial No. 531,908

6 Claims. (Cl. `23328) In the manufacture of various kinds of cheese.

it is customary to take curdled milk or its equivalent, add thereto butterfat in proportions varying-fromnought to ten per cent. ofthe total mix, dependent on the kind of cheese to be made. subject the mixture to the action of a homogenizer, and then, by a long established conventional procedure, including a prolonged period of drainage, separate the whey or serum, leaving a product composed mainly of butterfat and milk solids. One of the serious objections to the conventional methodof cheese manufacture is that the prolonged time required for the separation of the whey or serum eifects physical or chemical changes, or both, that deleteriousiy affect the flavor, and particularly the lkeeping qualities, of the cheese.

A primary object of my invention is to pro-v duce cheese of superior flavor whose keeping qualities are greatly superior to cheese produced by conventional methods. I have found that if the separation of whey or serum is eifected tion of cream from whole milk, or to separate liquids from solids, whether the solids are heavier or lighter than the liquid, as. for example, in the separation of wax from a chilled soultion of mineral oiland diluent-are not adapted to the separation of the whey or serum from the butteri'at and solids constituting the cheese constituents. I have found it necessary, in order to satisfactorily 'accomplish this purpose.. to design a special type of centrifugal separator, and

such centrifugal separator, embodying as it does.

certain new and useful structural features, forms the subject matterof my invention. The drawing isfa vertical sectional view of the improved centrifuge and of auxiliary means `i'or conveying the separated constituents toward their respective ultimate receivers.

The bo'wl body is of conventlonalconstruction andv comprises a bottom b having an upright sleeve c -for the recepition of the driving spindle a, a shell d and a top e, the latter being'secured to thesneuabymeansofanngfthreaaedonthe.

shell d and having a flange overlying the periphpurifying chamber or distributor of relatively small capacity and an outer annular separating chamber of relatively great capacity. 'I'his partition has a neck h2 extending'from its upper l0 end. Into this neckextends the lower end of a feed 4tube g. The partition h extends vnearly to the bottom of the bowl and has at its lower and wider end an inwardly extending flange h! over the inner edge of whichthe homogenized mixture ilange into the outer or separating chamber. Since there is onlyv one outlet from the inner 20 chamber'to the outer chamber, substantially the entire mixture fed throushihe feed tube a enters the outer chamber. If, however, the mixture' .contains any heavy solid impurities, the mild centrifugal force operative inthe inner chamber 25 will effect their separation, and such limpurities will accumulate in theangle formedA between the l The proportionpartition hf and its flange h'. of such impurities is, however, so small that the centrifuge will operate for a prolonged time with- 3 out excessive accumulation thereof.

InA the outer chamber occurs the separation ofthe whey .or serumlfrom the lighterbutterfat and solids. The serum is heavier'than the cheese constituents and will'therefore be thrown tothe '35 periphery,`while the lighter constituents will be inward. Theserum continually escapes at the periphery of the bowl into an annular chamber i enclosed by the upper end of l shell d, the -lower end ofv top e and'a flange e'- 40 depending from the top e, `and thence hows, 1 through a channel or channels i' in the bowl top, into an annular chamber :I between the bowl top and the neck h of the' partition h. The upper and lower walls of this chamber' extend to and 5 centralise the neck h of the partition h. The

outside diameter of this neck is substantially less than the 'diameter of the opening at the bottom of rthe inclined wall o' (hereinafter described), thereby preventing :escape of liquid from the "5 chamber! intothe chamber (o) within wall o.- The serum 'escapes from chamber i vthrough a nozzle lc and -discharges into a stationary receiving pan or trough m, 'whence it flows into a pipe n communicating with the ultimate receiver (not shown) for the. serum.

The separated relatively solid cheese constitutation, are not free owing. In an ordinary centrifuge, they would accumulate in the central separating zone and clog the discharge. Where, however, the inner zone is bounded by the fr ustoconical partition h, the cheese constituents will continuously slide along the partition wall and continuously and freely discharge into a chamber o formed by the lower wall of chamber i and a wall o extending downward therefrom in a direction inclined to the axisof rotation of the bowl.

There is no novelty, broadly, ina centrifuge which contains a partitioning member, providing an inner chamber for preliminary separation of heavier solids, having an inwardly projecting flange under which the mixture flows from the inner chamber to the outer purifying chamber. such construction being known, for example, in purifying bowls of which one is shown in lthe Leitch Patent No. 1,370,326. The outer or main purifying chamber of such a centrifuge, even if it were provided with an outlet from the outer chamber for separated heavier liquid, would not have the mode of operation above described and would not be adapted for the separation 'of cheese constituents from whey.

Nor is there any noveltyin the broad principle of operation of an inclined partition for facilitating the' outflow of a separated constituent. Such amember is disclosed in thelAndersson 8: Dahlgren Patent No. 1,821,607, dated Sept. 1, 1931, which discloses an element, inclined toward the axis of rotation, adapted to facilitate the travel of the lighterseparated constituent from the locus of separation inwardly toward the axis of the bowl. In the Andersson et al contrivanee.

convey the the inclined element functions both lighter separated constituent along its outer wall toward the bowlsV axis in a direction away from the ultimate discharge outlet and also to conf vey such constituent along its inner wall away from the bowls axis, in the opposite direction,

toward the ultimate discharge outlet. In my iinprovement thelighter separated constituent is conveyedalong the wall of the partition h in a direction toward the ultimate discharge outlet. into a separate chamber o, and thence in the same general direction." along the inner face of the frusta-conical wall o' (forming the outer wall of the -chamber o) toward the ultimate` discharge outlet. The frusta-conical partition h should extend up as high as, or preferably somewhat higher than. the-cylindrical part of the bowlshell.

The discharge outlet comprises one or more tubes p extending through the chamber i into a receptacle r located above chamber j and formed by an annular flange r' vextending up from the chamber i .and having an inwardly extending annular lip r. over which the. separated lighter cheese constituent' escapes into .a surrounding stationary receiver t'supported above the 'receiving pan m.

Extending downward from the bowl top, into the annular V-shaped space between the bowltop and the wall o' are one or more annular flanges forming dams s, which, with the conical wall o', arrest the flow ofany heavier liquid constituent that may be displaced inward in a shallow stream along the bowl 'top wall and thus pre vent its flow into and discharge with the solids into the chamber o. By thus arresting any such inward movement of the heavier liquid it is insured that there shall be a substantially com- .ents, displaced inwardly toward the axis of ro-A plete discharge of all`such liquid through the channels i.

Secured to the top of the neck h2 of the partition his a cover u which extends over and beyond the receptacle 1' and narrowly clears the iiange r2. The discharging lightercheese constituent is thus discharged in a ne spray into the chamber t.

The temperature of the mixture admitted through the feed tube g should be above 140 F. and below the boiling point of the liquid constituent of the mixture, a temperature of about 180 F. being preferable; and thistemperature is maintained, or nearly maintained within the centrifuge. Because subjection of the mixture to prolonged high temperature may cause chemical `changes that may result in irregular operation, the heat should be applied quickly in a. continuous heater located near to the centrifuge. It is desirable tomaintain heated, although not necessarily or desirably to the temperature withinthe centrifuge, the receiving pan t, and this maybe effected by a jacket t' enclosing the reciving pan -t and heated byV any suitable fluid heating medium. If the pan is thoroughly insulated, the desired temperature will be attained in a few minutes at the start of a run and maintained until the end of the run. Nevertheless, there is a tendency toward clogging just beyond the inner edge of the upper wall of the trough m, with re- Y sultant danger of diversion of some of the sepof the cheese arated'cheese constituent into the trough m. This Ais prevented by providing a cutter o that depends tfrom the outeredge of the cover u and prevents any such clogging or shaves away any slight accumulation of cheese that may form in a. single revolution of the bowl.

Due partly to the drop in temperature in the receiving pan t, but due mainly to the discharge im a fine spray into the receiving pan, sub stantialand desirable aeration of the cheese would occur if no means were provided to prevent it. I have found that the provision of a hood w of restricted diameter extending into the receiving p an t and down below the level of the cheese discharge eectually. prevents such aeration.

The separated cheese constituent leaves there;

ceiving pan t through a hole in its bottom, passing thence intoV a pipe m leading to an ultimate receiver (notshown). In order to sweep the cheese around the receiver into the pipe there is provided one.or more scrapers or conveyors y;

which are given a siowmovementof rotation. Such a conveyor is desirably a wing or vane extending (radially or somewhat backward from a radial line) from the edge of cover u to, and just clearing, the outer wall of the receiving pan t and extending upward from barely above the bottom of the receiving pan t. The said movement of rotation may be effected by securing the wing y to the hood w and by securing the -hood w to a' flange on a sleeve z on the feed pipe g. This sleeve may be rotated slowly by a belt (not shown) engaging a pulley z on said sleeve.

I naive round it desirable to locate the chamber r for reception and discharge of cheese above the chamber i for reception and discharge of serum so that the cheese may be discharged into the upper cover, which can be readily equipped with the hereinbefore described mechanism for sweeping the cheese out of the cover and also screened to protect it from oxidation and heat losses. It

would be dimcult to. apply these expedients to i the lower cover.

chamber having a discharge outlet for the separated lighter constituent.

4. A centrifuge adapted especially for the sepa-V ration of cheese constituents from whey or serum of higher specific gravity comprising a rotatable bowl, a frusto-conical member within and rotatable with the bowl providing an inner wall for the separating chamber and extending from its wider end near one end of the bowl and near its peripheral wall toward the axis of the bowl, said separating chamber having a peripheral outlet for the heavier liquid constituent, an inclined wall extending from the top of the separating chamber downward and inward toward said truste-conical member and spaced therefrom to form an outlet for the lighter constituent at about the narrow end of said frustro-conical member, said inclined wall forming the outer wall of a chamber which communicates with the oulet for the separated lighter constituent and which is provided with an outlet for the discharge of the lighter constituent, said bowl having a frusto-conical top the upper end of which adjoins the upper end of said inclined wall, said inclined wall forming the inner wall of the upper part of the separating chamber, and one or more dams extending downward from the bowl top and adapted to prevent flow into the inner or central zone of the separating chamber of any heavier liquid that may be carried into the upper portion of the separating chamber between the frusto-conical top and said inclined wall.

5. A centrifuge adapted especially for the separation of cheese constituents from whey or serum of higher speciilc gravity comprising a rotatable bowl, a frusto-conical member within and rotatable with the bowl providing an inner wall for the separating chamber and extending from its wider end near one end of the bowl and near its peripheral wall toward the axis of the bowl, said separating chamber having a periph-` eral outlet for the heavier liquid constituent and an outlet for the lighter constituent at about the narrow end of said frusta-conical member, said bowl having an annular wall inclined to the axis and 4extending from and beyond said outlet in a direction inclined away from the axis and forming the outer wall of a chamber communieating with said outlet and adapted to receive therefrom said separated lighterconstituent and provided with an outlet for discharge from said chamber of said lighter constituent, a receptacle 8 Y rotatable with the bowl and communicating with the outlet from the last named chamber, a cover for the receptacle spaced from'the upper outer 6. A centrifuge adapted especially for the separation of cheese constituents from whey or serum `of higher specific gravity comprising a rotatable bowl, a frusta-conical member within J and rotatable with the bowl providing an inner wall for the separating chamber and extending from its wider end near one end of the bowl and near its peripheral wall toward the axis of the bowl, said separating chamber having a periph#l charge outlet for the separated lighter constitu ent, the upper of said three chambers being provided with a wier and a cover for said-chamber extending over said-wier and beyond the outer wall of said upper chamber to provide a narrow opening forming the specified discharge outletfor the lighter constituent.A

GEORGE J. BTREZYNSKI.

REFERENCES crrnn The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,370,320 Leitch Mar. 1, 1921 1,821,607 Andersson Sept. 1, 1931 2,216,442 Lindgren Oct. 1, 1940 FOREIGN PATENTS Number Country Date Great Britain Oct. 28, 1928` t Certificate of- Correction lo Patent No. 2,461,129. February 8, 1949.

GEORGE J. STREZYN SKI It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: f

Column 4, line 41, for the word desirable read undesirable; column 5,' lines 68 gud 69, claim 1, for separating chamber, said bowl read bowl, sa'd separating chamer; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of August, A. D. 1949.

THOMAS F. MURPHY,

Assistant Gommsagner of Patents. 

